Photovoltaic green roofs and facades

Abstract

The invention relates to a green roof system characterized in that same comprises: a. a support (10), a. plant growth modules (40) each comprising a sealing membrane and a multilayer culture complex successively comprising at least a first fibrous synthetic material and a flexible mesh, b. a plurality of bifacial orientable photovoltaic panels (21 to 23) arranged above the plant growth modules.

Description

PHOTOVOLTAIC GREEN ROOFS AND FACADES Field of invention

[0001] The present invention relates to the field of value-added roofs and facades and more particularly to green roofs and facades equipped with adjustable photovoltaic panels.

[0002] An example is illustrated by the PROOF (Photovoltaic and green ROOF) project led by the National Institute of Solar Energy (INES), combining extensive green roofs (EGR) and photovoltaic panels, to meet different benefits: Incident solar energy in the summer dissipated by a green roof mainly in the form of latent heat flow, creates a reduction in localized air temperature and provides favorable conditions for increasing the electrical efficiency of a photovoltaic panel; An extensive green roof with a structure that can store rainwater, promotes evapotranspiration flows and can therefore further improve the panel's efficiency; At the building scale, the overall energy balance (energy production / consumption in use + gray energy) is more advantageous for a combined system than for a standard bare or green roof terrace;Compared to a classic roof configuration, a combined system provides additional ecosystem services, which can be assessed and valued at the neighborhood scale.

[0003] Combining a green roof with solar panels improves energy performance: The vegetation captures dust and particles, so fewer of them end up on the solar panels. As a bonus, the plants' evapotranspiration makes the air cooler, which helps cool the solar panels. They therefore absorb less heat, for better efficiency. Combining vegetation with solar equipment therefore increases energy production while improving the building's insulation.

[0004] In Sydney, for example, a difference of almost 20 degrees Celsius between a solar surface and a hybrid greenery / solar panel surface was observed.

[0005] The combination of a green roof and adjustable solar panels also protects vegetation from direct solar radiation by the shade cast by the panels located between the green roof and the sun. This shaded protection limits evapotranspiration flows and contributes to saving water consumption linked to irrigation. State of the art

[0006] Patent SE414804 describes external roofs for buildings intended to be overgrown with vegetation and comprising an underlying waterproof layer and a layer of material above which plants, in particular grass and the like, can grow, characterized in that the underlying, waterproof, layer consists of corrugated sheets arranged with their grooves extending in the inclined direction of the roof surface, and said cultivable layer consists of a plurality of separate sheets of a material in which plants can grow, which sheets are placed next to each other and at a distance from each other at least in the inclined direction of the roof surface on the underlying corrugated sheets and are held thereon by means of the same holding means.

[0007] Patent KR101572859B1 describes a photovoltaic installation support, and more particularly, for installing a photovoltaic installation capable of producing solar energy representative of renewable energies in any location and minimizing the installation of the structure used therein.

[0008] Patent KR101572859 describes a hybrid greening system for the rooftop that is installed on top of the rooftop to improve the energy efficiency of the building on which the rooftop is installed and to reduce the flow of rainwater during rainy weather. A vegetation unit having a partition wall and having an upper surface formed therein and installed in the roof plate.

[0009] Patent KR20130142977 describes a solar cell module system allowing a solar cell to be stably installed in a roof.

[0010] Utility model CN204392150 describes a photovoltaic module with a roof without photovoltaic guide rail support, it is characterized in that, comprising: a photovoltaic module connector, is connected to the photovoltaic module; the clamping element, is connected to the roof, with a rotation between the photovoltaic module connector and the clamping element.

[0011] Disadvantages of the prior art

[0012] Prior art solutions have several disadvantages. Firstly, they add a significant load to the roof and building structure, which makes the solution inapplicable for many buildings whose strength is not sufficient.

[0013] Prior art solutions also deteriorate quickly because solar panels create shade that is not conducive to plant growth.

[0014] Finally, the wind resistance of these prior art solutions is significant, and in areas with known severe atmospheric conditions (strong winds, storms, cyclones), these solutions are not appropriate.

[0015] Prior art solutions limit the optimal exposure time to solar radiation because the photovoltaic panels are arranged in a fixed and immobile manner.

[0016] Solution provided by the invention

[0017] In order to overcome the drawbacks of the prior art, the present invention relates, in its most general sense, to a green roof system characterized in that it comprises:a support formed by an assembly of folded sheetsvegetated modules each comprising a waterproofing membrane and a multi-layer culture complex successively comprising at least a first fibrous synthetic material and a flexible mesha plurality of adjustable photovoltaic panels.Detailed description of a non-limiting example of embodiment

[0018] The present invention will be better understood on reading the following description, concerning a non-limiting example of embodiment illustrated by the appended drawings where:

[0019] represents a three-quarter perspective view from above of a system according to the invention

[0020] represents a sectional view of a system according to the invention.

[0021] General principle of the invention

[0022] The invention is based on a modular system for fitting out a roof, in particular a flat roof with no inclination limit or a terrace roof, consisting of laying a support formed by folded metal sheet plates (10) or any other material (concrete, zinc, slate, wood, etc.), for example roofing or cladding sheets having parallel ribs. Such sheets are commonly used as cladding for a building, whether on a roof or a facade. There are, in a known manner, sheets equipped with identical and adjoining ribs. Such uniqueness makes it possible to stack several sheets, which facilitates storage and transport. On the other hand, this implies that sheets of a given type are transported and / or stored, therefore to produce a uniform building cladding, at least as regards the configuration of the ribs of the sheets.

[0023] The term "ribbed" should be understood here as designating a relief, positive or negative, therefore a hollow or a bump made on the sheet. This relief is at a different altitude from that of the average plane of the sheet. The shape, number and / or distribution of the ribs on the sheet are variable. The ribs are parallel to each other. The ribs are identical on the same sheet or form a pattern that is repeated on each sheet.

[0024] The system also includes photovoltaic panels (21, 22, 23) positioned at least partially above the vegetated areas so as to benefit both from cooling by the plants, improving photoconversion performance, but also to shade the plants to protect them from direct solar radiation.

[0025] These photovoltaic panels (21, 22, 23) are advantageously articulated relative to transverse axes (31 to 33) forming hinges relative to the support (10), to allow the orientation of the photovoltaic panels (21 to 23) to be adjusted.

[0026] The connection between the axes (31 to 33) and the support (10) is ensured by angles which are fixed to ribs of the support for example.

[0027] The photovoltaic panels (21 to 23) can be folded flat, parallel to the plane (10) of the support, or erected to be directed towards the sun, the panels being moved angularly to maintain parallelism between them. The actuation of the panels (21 to 23) is controlled by a drive system consisting either of motorized hinges or bearings on which the photovoltaic panels rest or of belts or chains (20) driven by motors (24 to 27) and fixed on the upper edge of the photovoltaic panels (21 to 23) or by a mechanism similar to that of a bioclimatic pergola where the photovoltaic panels would replace the blades of the pergola so that their positioning according to the position of the sun allows the sun to be partially reflected on the rear face of the adjacent bifacial PV panel and so on on each panel.

[0028] When the panels are folded down, they reduce wind resistance and protect plants, particularly during tropical storms.

[0029] The system finally comprises vegetated modules, for example of the type described in patent EP3755140. This module comprises a base (41) which is placed on the support (10). This rigid and waterproof base (41) is completed by a multi-layer culture complex successively comprising at least a first fibrous synthetic material (42) and a flexible mesh (43) and optionally a second fibrous synthetic material (3).

[0030] These vegetated modules (40) are inserted between the hinges (31 to 33) of the photovoltaic panels (21 to 23).

[0031] During electricity production periods, the motors (24 to 27) control the tilting of the photovoltaic panels (21 to 23) into the active position, oriented towards the sun, with an orientation that can change to follow the path of the sun.

[0032] Outside of these periods, the photovoltaic panels (21 to 23) can either be folded horizontally to reduce wind resistance and protect the green modules (40), or on the contrary placed in a position allowing the sun to illuminate the green modules (40).

[0033] The vegetated modules (40) may also include an irrigation system controlled by a pump powered by a battery recharged by the photovoltaic panels (21 to 23).

[0034] The foregoing description relates to photovoltaic panels (21 to 23) which may be fixed, inclined at an angle suitable for exposing the largest surface area perpendicular to the direction of the sun, which allows them to benefit from cooling by the plants and form an inclined screen limiting wind resistance. They may preferably be foldable by pivoting around an axis provided in the lower part of the photovoltaic panels (21 to 23) so that in the event of bad weather or tornadoes, they may be placed horizontally to reduce wind resistance and form protection for the plants. The photovoltaic panels (21 to 23) may also be hinged relative to a central or upper axis to ensure that they are held in an inclined position.

[0035] Variant: bifacial panels

[0036] According to an alternative embodiment, the panels are of the bifacial type, i.e. they have photovoltaic cells on both sides, in order to exploit indirect radiation (reflection of solar radiation on a neighboring panel, albedo, etc.).

Claims

– Green roof system characterized in that it comprises:a support (10)green modules (40) each comprising a waterproofing membrane and a multi-layer culture complex successively comprising at least a first fibrous synthetic material and a flexible mesha plurality of adjustable bifacial photovoltaic panels (21 to 23) arranged above said green modules. – Green roof system according to claim 1 characterized in that each of said adjustable photovoltaic panels is articulated to switch between a position parallel to said support, and a position oriented towards the sun. – Green roof system according to claim 1 characterized in that each of said photovoltaic panels is articulated relative to an axis to tilt relative to its lower edge. - Green roof system according to claim 1 characterized in that each of said adjustable photovoltaic panels is rotated between a position parallel to said support, and a position oriented towards the sun by belts or chains (20) driven by motors (24 to 27) and fixed on the upper edge of the photovoltaic panels (21 to 23). - Green roof system according to claim 1 characterized in that each of said adjustable photovoltaic panels is rotated between a position parallel to said support, and a position oriented towards the sun controlled by a drive system consisting of motorized hinges or bearings on which the photovoltaic panels rest. - Green roof system according to claim 1 characterized in that it further comprises profiles arranged transversely on said support, said profiles comprising a hinge for the articulation of one of said photovoltaic panels, said profiles separating two consecutive green modules. - Green roof system according to claim 1 characterized in that said photovoltaic panels are of the bifacial type.

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